The display device using electron beam has been hitherto used as a display device in video appliances and the like.
A conventional electron beam display device is described with reference to FIG. 1. FIG. 1 shows the principle of a flat plate type display device using electron beam. Electrodes are disposed in a vacuum container not shown in the drawing, and number 1 is a back electrode, and 2 denotes a plurality of linear cathodes which emit electron beam. Number 3 is an electron beam focusing electrode, 4 is a modulation electrode, 5 is an electron beam focusing electrode, 6 is a horizontal deflecting electrode, 7 is a vertical deflecting electrode, 8 is a face plate, and 12 is an electron beam. FIG. 7 is a detailed sectional view of the face plate. Number 9 denotes a fluorescent element and 10 is an anode composed of an aluminum layer. When the cathode 2 is heated, an electron beam is released, and passes through the electron beam controlling electrode group, and collides against the anode 10 to illuminate the fluorescent element 9, thereby forming an image (Japanese Laid-open Patents Sho. 61(1986)-124043, Hei. 2(1990)-78139).
However, when an electron beam is irradiated to the anode of the conventional flat plate type electron beam display device, part of the electron beam is reflected by the anode and come back to the cathode side. The reflected electrons are returned back by action of high electric field applied between the cathodes and anodes for accelerating electron beam, and again dived into the anode. These reflected electrons cause dim lits in the surrounding area of the electron beam irradiation point, which is called "halation". In particular, when the anode voltage is raised, the energy of the reflected electron is increased, and this phenomenon becomes more serious. This phenomenon was a serious problem for image performance because the image contrast is lowered and the sharpness is sacrificed.
In order to reduce the halation, it has been proposed that a shadow mask is disposed in front of the anode electrode to trap electrons reflected from the surface of the anode electrode layer, thus preventing returning the electrons back into the anode electrode layer. However, the formation of the shadow mask makes the structure complicated and makes the process for producing the display device complicated.
It is also proposed that carbon particles or graphite particles dispersing a binder over the aluminum layer are applied by coating means of spray method, printing method or the like (see FIG. 8). The carbon particle layer 11 suppresses the reflection of electrons. The carbon particle layer, however, has not been studied yet in details and therefore excellent technical effects have not been obtained.